Improvement in exhaust mechanisms



G. BUNKER.

Exhaust-Mechanism.

Patented July 13 WvbmeM u:

N. PETERS. FHBTO-LITHOGRAPMER, WASHINGION. 0 C.

UNITED STATES PATENT OFFICE.

. GEORGE BONKER, OF PORT JERVIS, NEW YORK- IMPROVEMENT IN EXHAUSTMECHANISMS.

Specification forming part of Letters Patent No. 165,437., da ed July13, 1875; applicati -n filed 7 June 12, 1875.

To all whom it may concern:

Beit known that I, GEORGE BONKER, of Port Jervis, in Orange county, intheState of New York, have invented certain new and useful ImprovementsRelating to Draft-Begin lators, of which the following is aspecification:

The invention is designed more particularly for the smoke-boxes oflocomotive-engines; but it may be usefut when correspondingly placed inconnection with other high-pressure engines and boilers.

I use the ordinary steam-jet as a means to quicken the draft. It ishighly convenient to discharge the steam under all conditions throughthe same nozzles, mounting them in the position that is most efl'ectivein promoting the draft; but there are many conditions under which it isdesirable to discharge the steam through the nozzles without therebyquickening the firc.l

The object of my invention is to provide for varying the conditionswithin very wide limits.

There are practical objections to the opening and closing ofexhaust-nozzles. It has been found in practice that a sufiicientforcingof the draft could be obtained with such a capacious blast-orifice aswill not induce a serious back pressure on the piston. A new conditionis, however, developed in the use of judiciously-constructedlocomotives, in that the draft is liable to be too much forced undersome conditions.

There is much of the time in hauling light trains, or even in haulingheavy ones, over level portions of the'track when the 1ocom0- tive willmake steam too freely in consequence of a too powerful urging of thefire by the strong blast of steam up the chimney.

In one condition of my apparatus the steamjet is in the highest degreeefficie-nt in promoting the draft. In another condition the effect ofthe steam-jet in promoting the draft is so slight as to be almostinappreciable.

The apparatus may be adjusted in various intermediate conditions atwill.

The accompanying drawings form a part of this specification, andrepresent what I consider the best means of carrying out this invention.

Figure 1 is a cross-section through the smoke-box of the locomotive, andthrough the blast-pipes and other principal parts. Fig. 2 is a sideelevation corresponding thereto, and Fig. 3 a cross-section.

The strong lines in Fig. 1 show the parts adjusted for the strongestdraft. The dotted lines in the same figure show the parts partiallylowered to reduce the draft.

Similar letters of reference indicate like parts in both the figures.

The drawings show the novel parts with so much of the ordinary parts asis necessary to indicate theirrelation thereto.

A is the barrel or cylindrical shell of the smoke-box; and A" theoutside or main chimney attached to the smokebox as usual, and adaptedto perform its ordinary functions of conducting upward the hot gases andthe exhaust steam. B B are exhaust-pipes, receiving steam in strongblasts from the cylinders and delivering it upward in or near thecentral line of the chimney from the nozzles b b. (J is'aPetticoat-pipe, formed with. a vertical slot, 0, .on each side, and heldstationary by braces (not represented) over the blast-nozzles b b,- andG is a flaring bottom thereof, which extends below the ends of theblastnozzles. B is a convex shell mounted in the position represented, alittle below the mouths of the blast-nozzles b.

There is ample space between the edges of B and G for a large portion ofthe products of combustion to move freely; and except for further parts,t be described, the discharge of the steam through the blast-nozzles bwould always induce a very vigorous draft, a large portion of theproducts of combustion being drawn under the flaring mouth 0 and urgedup the interior of the pipe 0.

D D are lengths of pipe, the first, D fitting easily within thevpetticoat-pipe O, and the second, D mounted a considerable distanceabove it, and being held in a concentric position within the chimney Aby means of wings, so that it is free to be moved up and down,maintaining its concentric position. The parts D and D are connected byside rods d (1, connected to brackets, as shown. The lowermost brackets,d, are fixed on the pipe D moving freely in the slots 0 in the pipe C.

H is connected to another arm, E on the shaft E, and leads to thevicinity of the engi' neer, where provisions are made by notches orotherwise for holding it atwill in any desired position.

The parts are so proportioned that when the arms E are in their highestposition the pipe D is entirely within the petticoat-pipe 0, and is ofno effect. The pipe D is also at a considerable height in the chimney,and as it is of little thickness, and the products of combustion areallowed to move freely inward and outward below it, it is oflittleeffect. It exerts a slight influence in inclosing the violent currentsof steam ejected from the nozzles b, and causing them to act efficientlyon the products of combustion, which have free access thereto not onlyunder the flaring petticoat-pipe 0, but also again between the pipes Dand 1).

When the engineer wishes to reduce the draft he moves the rod H andturns the shaft E, so as to lower the pipes D I) more or less. Inproportion as he does this the draft is diminished without affecting theescape of the steam, orin any way materially modifying its flow up theinterior of the chimney. When, in an extreme case, as, for example, onthe last part of an ascent immediately before descending a grade, thelocomotive is discharging steam from its nozzles b with full force, butit is desired not to thereby increase the draft in the furnace, theengineer draws the arm E as far as possible, thereby lowering the pipesI) and 1) to their extreme lowest position. Thus situated, the loweredge of the pipe D matches down upon the c011- vex shell B, forming analmost gas-tight joint therewith, clear around. This prevents any of thegaseous products of combustion from entering the pipe D. The samemovement brings the lower edge of the pipe D to match upon and a littlewithin the upper end of the petticoat-pipe O. This forms an almostgas-tight joint there, thus preventing any of the products of combustionfrom entering the pipe D. It follows that in this condition of theapparatus the exhaust steam is ejected from the nozzle 11 through theentire space inclosedwithin the pipes D 0 D up to the top of D withoutexerting any influence on the products of combustion, which rise,sti'mulated only by their natural levity, through the annular spacebetween the outside chimney A and the said internal pipes, and only comein contact with the exhaust steam after their ascent above the upperedge of the pipe D The pipe I) may be carried quite to the top of thechimney A, if preferred in any case; but, for general practice, I preferto leave it at about the height indicated in the drawings. The slightaction of the ascending current of steam upon the hot products ofGOmbuStiOn near the -top of the chimney does not force the draft to suchan extent as to be serious.

Care should be taken, in the proportioning .of the parts,-to leave asufficieiit space between the inner pipes O'D D and the outer pipe orchimney proper A, to allow a reasonably-free escape for the products ofcombustion. In ordinary working, however, the pipes D D will bepartially or entirely raised. The engineer should raise them to theirhigest extent, so as to promote the draft in the highest degree, inascending grades, or whenever a vigorous action of the fire is desired.Under circumstances where less forcing of the fire is desired, he willlower them until only the proper amount of force is applied to thedraft. As they are raised and lowered, a space for receiving theproducts of combustion is increased and diminished, not only under thelower edge of the lower pipe D but also underthe lower edge of the uppersection D I can divide the movable 'pipe D D into more than twosections, similarly mounted with regard to a correspondingly-increasednumber of stationary pipes C; but I believe two sections, andconsequently two spaces, to

. apparatus is worked in the closed condition.

The shell B may, if preferred, have a sinr ple conical form, instead ofthe spherical fornr represented. I esteem it important that it shalltaper, as it aids in deflecting the current of gases upward when theapparatus is nearly closed, and contributes to accurately center thepipes when they are in the lowest position.

My invention can be used in combination.

1. The tapering-formed shell B, arranged as shown, relatively to theblast-nozzles b and movable pipe D, and receiving the lower edge of thelatter on its swelled surface, and compelling it to rest concentricallythereon, tor the purposes specified.

2. The movable sections D D and means for elevating and depressing them,in combi-.

nation with the petticoat-pipe O, blast-nozzles b, anda stop-disk orshell, all arranged to 0p erate relatively to each other and to the in-In testimony, whereof I have hereunto set closingchimney A, as and forthe purposes my hand this 8th day of June, 1875 in the herein specified.presence of two subscribing witnesses.

3. The flaring mouth 0 and the petticoat- GEORGE BUNKER. pipe 0,arranged, as shown relatively to the Witnesses: lower section D and tothe nozzles 12 and stop- WM. 0. DEY,

surface B, as specified. HENRY GENTNER.

